The invention relates to an accelerated life test platform for a water pump of a converter valve cooling system and a test method of the accelerated life test platform. The test platform comprises a pressurizing system, a driving system and a temperature control system, wherein the pressurizing system, the driving system and the temperature control system are connected through a circulating pipeline, so that a closed loop is formed. A heat source device, a temperature measuring device, a pressure sensor, a booster pump and a programmable logic controller (PLC) variable-frequency device of the test platform are all connected with a central processing unit, and a command is given out through the central processing unit to achieve automatic control over the test platform. Through the test platform, an accelerated life test of a pressure acceleration factor, an accelerated life test of a rotating speed acceleration factor and an accelerated life test of a temperature acceleration factor can be achieved; the average life of the water pump under the normal stress level condition is extrapolated by means of the average life of the water pump under the accelerated stress level condition, so that the acceleration factors are determined, and evaluation of the performance of the water pump is achieved. The accelerated life test platform for the water pump of the converter valve cooling system and the test method of the accelerated life test platform have extremely important significance for shortening the research and development cycle and improving the reliability of the water pump, and reliable test data are accumulated for the research and development of high-performance, high-pressure and large-flow water pumps.